networkadmin-select] Local Area Network

please, does anyone know of a software we can run to detect where and
if we are having problems with our LAN?

Our satellite link slows down and the NOC told us wehave a LAN/cable
problem, we do not know the exact PC with cable, so we thought there
should be a software that would detect the Local Area Network and
tell/show us the exact location or cable thats having problem.

Do you and your company have a baseline, or a service level agreement with
the noc?
Generally speaking, satellite links are pretty slow. When the noc says you
have a
lan/cable problem, that sounds a bit vague to me, because when you think
about it,
take away the lan and the cables and you have nothing! Seriously though,
it you were
to thoroughly review your lan, it might be helpful to have a network diagram.

The diagram could include all you lan components, as well as all the
satellite components
and who they are managed by (the same noc that you refer to, or another
provider?). Then,
you could check for problems with connectivity using cable testers, etc.

By the way, which applications are you using when you notice slow
response? Are all
applications equally slow? As you evaluate your network a baseline could
include not
only general ping response times, but response times for different
applications that you use.

Don't give up, make the noc do their job!

Good luck,
Keith

At 11:03 PM 7/24/2003 -0700, you wrote:
>Networking daily news - http://www.ittoolbox.com/i/nw9.asp>
>hello all,
>
>please, does anyone know of a software we can run to detect where and
>if we are having problems with our LAN?
>
>Our satellite link slows down and the NOC told us wehave a LAN/cable
>problem, we do not know the exact PC with cable, so we thought there
>should be a software that would detect the Local Area Network and
>tell/show us the exact location or cable thats having problem.
>
>Any assistance will be appreciated.
>
>Warm Regards,
>
>Ade
>
>
>
>
>=========================================
>Please, visit www.skywebafrica.com for your VSAT Solutions, Very affordable!
>
>
>

Keith is right. I am a Network/Voice tech for a Nat'l Data Center and it is the job of the NOC to trace the routes section by section, router by router, switch by switch. You should assist them from your end at the closets, but it should be mainly in their ballpark. Before you attempt to use any sniffing tools to try and see packet loss make sure that it is approved software...that can make a big mess if not.

Keep it simple, Put a fluke tester on each cable and see if you have a
difference in bandwidth on any one of them, if so change it and see it the problem
is corrected. If this does not locate your problem check each cable all the way
back to your point of presence.

Candela Technologies' LANforge platform excels at several different aspects
of
Network related testing and simulation. The LANforge-FIRE configuration is
used
for Traffic Generation, and will be used to simulate the edge of the network
you
are testing. The LANforge ICE configuration is used to simulate the core of
a
network, and will be used to test and verify equipment that communicates
through
the core. LANforge ICE can be used to replace or augment any requirement for
having a T1, DSL, Satellite, Dial-Up and other limited speed or lossy
network
link in your network diagrams. LANforge-FIRE and LANforge-ICE are two
personalities of the same software, so they can even be configured to run
simultaneously on the same set of hardware.

The LANforge-FIRE platform can generate FTP, HTTP, TCP/IP, UDP/IP, Ethernet
and
custom payloads. It currently supports Ethernet (up to Gigabit), 802.1Q
VLAN,
and Token Ring networks. LANforge software includes support for testing file
systems, including network file systems like NFS and iSCSI. LANforge-FIRE
can be
configured in many different ways, offering Gigabit Ethernet support on the
high
end, and high-density and inexpensive 10/100 Ethernet ports for lower speed
applications. Using the MAC-VLAN feature one can emulate an entire subnet of
machines with a single LANforge machine. It is specifically designed to meet
the
requirements of testing today's Last-Mile and Metro-Edge systems which must
handle simultaneous customer traffic across a large number of ports,
equipment
including Digital Subscriber Access Multiplexers (DSLAMs), Cable Access
Systems,
and their respective Customer Premise Equipment like DSL and Cable modems.
Recent LANforge improvements make LANforge an appropriate tool for testing
higher-speed networks up to Gigabit line speeds.
LANforge-FIRE can also be an excellent choice for stress testing your own
Linux
hardware, especially server type configurations that rely heavily on
real-world
networking performance. For example, if you are trying to get an idea of how
well your new dual-CPU system with 2 Gigabit NICs performs, you could load
LANforge on each one (with your own custom compiled kernel if you wish), and
drive Ethernet, UDP, TCP, FTP and other traffic against other LANforge
enabled
stations. You could even use LANforge to start up file system tests
including
the respected bonnie++ program.
The affordable cost per port, ease of use, and standards compliant
networking
stack makes the LANforge an essential piece of equipment in every test lab.

LANforge-FIRE: The Business Case
Validates stability and data throughput on devices under evaluation.
Useful for testing any network, and especially cost effective for efforts
requring many data-generating ports, such as DSL, Cable-Modem, and
Satellite
modems.
Turn key solution. The LANforge systems come pre-installed and configured
based upon customer supplied information.
Implements a modular architecture that allows you to leverage your
existing
LANforge investment as your need for capacity increases.
Ease of use - Manage entire LANforge installation through one interface,
from
anywhere on the network.

Comprehensive management information detailing all aspects of the LANforge
system including processor card statistics, test cases, and ethernet port
statistics.
Contains 8 or more physical data-generating ethernet ports per 2U LANforge
chassis, and can be purchased in a variety of form factors.
Emulates up to 250 unique machines with one physical interface with the
MAC-VLAN feature!
Supports 802.1Q VLANs.
LANforge systems come pre-installed and configured with customer supplied
network information.
Automatic discovery of LANforge processor cards simplifies configuration
of
LANforge test equipment.
LANforge traffic generation and management software qualified on Red Hat
Linux.

Test Scenarios

Run simultaneous Raw Ethernet, UDP/IP, TCP/IP, FTP, and HTTP over the same
ethernet ports.
Identify dropped, duplicate, reordered and corrupted packets.
Create streams of various packet sizes and payloads, including:
Fixed payload size and contents.
Random payload size and contents.
Custom packets, including all headers, as specified by the user.
Use fine grain control over packet rate, including the ability to specify
bursty traffic to give a true representation of customer usage patterns.
Blast your system-under-test with line speed 64 byte packets with
randomized
MAC and TCP addresses, to see if it can survive!
Create regression scripts using LANforge perl libraries or your own
favorite
scripting language.
Change MAC Addresses and IP information dynamically with a script,
simulating
mobile clients.
Generate file system traffic to test local machine's performance.
Generate NFS and/or iSCSI file system traffic to test network and
network-storage devices.

Figure 1: Typical LANforge Installation

The LANforge system consists of a single manager, and one or more
rack-mounted
traffic generators (cards). The cards are connected to the manager over an
ethernet management interface so that all management traffic is out-of-band,
which ensures accurate reports regardless of the state of the network under
test. Only the data-producing ports should be connected to the device or
devices
under test.
The LANforge manager runs the management server, and potentially, the
LANforge
GUI (graphical user interface). Because the LANforge GUI connects to the
manager
over TCP/IP, it can be run remotely, and because it is written in Java, it
will
work on many different types of computers, including Windows, Solaris, and
Linux. Depending on your hardware and speed requirements, you can also run
the
GUI, Management Server, and traffic-generation server on a single Linux
system.
That allows the minimum LANforge-FIRE installation to be a single machine
with 2
or more ethernet interfaces.

Specific LANforge Example (DSL)
Suppose that you have a DSLAM you wish to test with the LANforge package.
The
DSLAM has one 10/100BaseT ethernet interface that goes towards the network,
and
supports ninety-six (96) CPE DSL modems. Each DSL modem has at least one
ethernet port for the customer's equipment (or LANforge) to connect to.

Figure 2: LANforge testing a DSL System

Specific LANforge Example (Cable)
LANforge can also test Data-over-Cable systems. The example below
illustrates
how you might set up LANforge to test a system that includes a router for
the
upstream data traffic.
Figure 3: LANforge testing a Cable Access System

Generating Line-speed UDP traffic
LANforge Release 3.5 supports linux kernel accelerated traffic generation
and
reception. This feature, known as LANforge Armageddon, will be able to
generate
line-speed packet rates on 10/100Mbps networks, and can currently generate
up to
860Mbps on Gigabit Ethernet networks.
LANforge Armageddon can also customize or randomize various Ethernet, IP,
and
UDP header fields, making it an excellent tool for break-it testing to see
if
your system-under-test can withstand the onslaught.

Testing Specific Protocols
LANforge Release 3.0 directly supports only the main Internet protocols:
Ethernet, UDP/IP, TCP/IP, FTP, and HTTP. Generally, these protocols will be
sufficient to test any network. Some users may want to specify their own
packets
for specific tests, and to that end, LANforge gives you the ability to input
any
ethernet packet directly onto the network. The LANforge GUI also offers some
protocol builders for common protocols like TCP/IP, UDP/IP, and Ethernet.
Generating World Wide Web (HTTP) Traffic
The World Wide Web generally uses the http protocol, which runs on top of
TCP/IP. Typical traffic is highly bursty and contains random sized
packets. It
is also largely uni-directional, with the bulk of the traffic flowing
downstream towards the customer. Because TCP/IP is a stream based
protocol, if
you are testing a device that routes (as opposed to a simple layer-two
bridge), then you will most likely want to have many relatively slow
connections flowing from a few LANforge ports representing servers to many
LANforge ports representing the clients. These Cross-Connects should have
bursty traffic rates, as well as random payload sizes.
With the advent of LANforge v3.0, the HTTP protocol is now directly
supported.
You can set up a web server (probably on another LANforge machine), and
tell
LANforge to download URLs at some specified rate (urls-per-10-minutes).
Unlike
browser tests, LANforge will not try to cache any values, so you will
always
get the traffic patterns you request!
Most other, non-streaming, protocols also run over TCP/IP. It has the nice
feature of using all available bandwidth, but it also slows down when the
network becomes congested. If you are trying to gauge the total-throughput
of
a system, TCP/IP Cross-Connects with large (4000 bytes or higher) payloads
will be the easiest method. Just tell the LANforge to run at a speed
higher
than your system-under-test can handle, and then watch the actual rate
that
LANforge displays.
Generating FTP Traffic
The other most popular Internet protocol is FTP. FTP generates highly
unidirectional traffic, in either the upload or download direction.
LANforge-FIRE supports FTP uploads as well as downloads. LANforge machines
also come with an FTP server, so you will not need any external equipment
to
do your testing, though you may use your own FTP server if you so wish.
Generating File-System Traffic
LANforge-FIRE can now be used to generate file-system traffic (ie read and
write to files on the local machine). You can specify, among other
features,
the size and number of files to read/write and the size of the individual
calls to the read and write system calls. You can also calculate and check
a
32-bit checksum on the reads & writes for correctness checking. Because
Linux
can mount file systems over the network, including NFS, SAMBA, and iSCSI,
this
feature can allow you to generate some more important network protocols as
well.
Generating File-System Traffic with bonnie++
LANforge-FIRE also integrates with the bonnie++ program, a well respected
file
system tester and load generator. LANforge can launch the bonnie++ program
and
can parse it's output and display it in a well documented manner on the
LANforge-GUI. Because bonnie++ is open-source, you can even get the code
and
change it according to your needs to do your own exotic tests.
Using LANforge to integrate generic programs
LANforge-FIRE can launch and display results from almost any command-line
Linux tool, such as ping and traceroute. LANforge facilitates your testing
by
providing a framework in which to run such tools and store their results
in a
centralized place. Contact Candela Technologies if you have questions
about a
specific program.
Simulating VOIP & Other Streaming Media
Voice Over IP (VOIP) and other streaming media protocols usually run over
UDP/IP. This is a connectionless protocol, and it may lose or re-order
packets
from time to time. However, it has much less overhead than TCP/IP, and
because
most streaming protocols are real-time sensitive, it is better to be fast
and
occasionally lose a packet, than to always run slow(er).
Many streaming protocols, including VoIP, are designed to run over
low-bandwidth dialup connections. To simulate this type of connection with
the
LANforge system, you could set up many UDP/IP connections of 56kbps or
slower
rate. Generally, the rate and packet sizes should be constant. For VoIP,
realistic packet sizes are 300 bytes or (more likely) less! If you wish to
simulate many streams at once hitting a gateway or concentrator, then
using
LANforge UPD Cross-Connects at higher rates, but keeping the packet size
small, will yield the most realistic tests. Each Endpoint in the
Cross-Connect
should run at the same rate if you are simulating VOIP or conferencing.
For
broadcast type services, the downstream traffic rate should vastly
outweigh
the upstream traffic.
To test faster streaming media, like video conferencing, you should use
UDP/IP
Cross-Connects with MTU sized (1472 byte) packets with rates of 256kbps or
higher.
Simulating TFTP (BOOTP/DHCP)
The Trivial File Transfer Protocol (TFTP) and Boot Protocol
(BOOTP)/Dynamic
Host Control Protocol (DHCP) are often used to boot network computers and
Customer-Premise-Equipment (cable/DSL modems). All three protocols run
over
UDP/IP. Generally, these protocols run as fast as their network will
allow, so
if you are trying to simulate this protocol you will want to tell LANforge
to
run at the highest speed possible without dropping more than 1% of the
traffic. These Cross-Connects should be of type UDP/IP and the payload
size
should fit into the MTU for your network.

Example LANforge-FIRE Hardware Configurations
In order to have a fully function LANforge testing system, you will need at
least one of the Data Generator units with at least 3 ethernet ports. From
this
basic configuration, you can add more data-generators and more ports to each
data generator. If you do not have Candela's Linux kernel patches installed,
the
minimal configuration is two machines with at least 2 ports each.
See the LANforge Standard Systems page for suggested configurations.

The LANforge-ICE platform is used to simulate T1, DS3, OC-3, DSL, Satellite,
Dial-Up, and other Wide Area Networks (WANs). LANforge-ICE can simulate many
attributes of a WAN, including latency, jitter, packet-loss,
packet-reordering,
packet-duplication and bandwidth constraints. At full OC-3 speeds (155Mbps),
LANforge-ICE has accuracy to within 5 miliseconds for latency and jitter,
and
the packet-loss, reordering, and duplication settings are per million.
LANforge-ICE can be configured to run entirely on a single laptop provided
by
Candela Technologies or a distributor, and it can also be configured on
rack-mounted units or your own Linux machines.

LANforge-ICE: The Business Case

Reduces lab and training costs by replacing expensive WAN hardware, such
as T1
and FrameRelay devices.
Automates testing with various scripting features and libraries.
Compact form factor and rack-mount chassis conserves valuable lab space.
Laptop form factor makes LANforge-ICE a friendly traveling companion, and
a
good option for trade shows and customer demos.
Validates stability and functionality of devices and programs functioning
across a wide variety of network conditions.
Very affordable, especially when compared to competitors.
Delivers advanced, remote, cross-platform, graphical management interface.
Implements a modular architecture that allows you to leverage your
existing
LANforge investment as your need for capacity increases.
Turn key solution. The LANforge systems come pre-installed and configured
based upon customer supplied information.
Ease of use - central management of entire LANforge system from anywhere
on
the network.

Product features
Able to simulate DS1, DS3, DSL, CableModem, Satellite links and other
rate-limited networks.
Can modify various network attributes including: line-speed, latency,
jitter,
packet-loss, packet-reordering, and packet-duplication.
Supports WanPath feature to allow configuration of specific behaviour
between
different IP subnets using a single pair of physical interfaces.
Available configurations include all-in-one Laptops and rackmount systems
for
stationary labs.
Allows packet sniffing and network protocol decoding with the integrated
Ethereal protocol sniffer.
Comprehensive management information detailing all aspects of the LANforge
system including processor card statistics, test cases, and ethernet port
statistics.
GUI runs as Java application on Linux and Microsoft Operating Systems
(among
others).
GUI can run remotely, even over a dial-up modem link to accommodate the
needs
of the users.
Central management application can manage multiple units, tests, and
testers
simultaneously.
Supports scriptable command line interface (telnet) which can be used to
automate test scenarios. Perl libraries and example scripts are also
provided!

Example LANforge-ICE Configurations
LANforge-ICE is usually installed on a single machine with two Ethernet
ports
free for use by LANforge. It takes exactly two ports to simulate a WAN link,
but
if you wish to run several WAN simulations simultaneously, you may order a
LANforge-ICE configuration with 4 or more ports.
See the LANforge Standard Systems page for suggested configurations.

Product specifications & List Prices
For a free, no-obligation quote, go to the LANforge Quote Generator. If you
don't have an account already, you will need to Create An Account.

LANforge Component Details
LF1000 Data Generator
The LF1000 is a 1U (1 Rack Unit) shelf that fits into a standard 19 inch
(wide) frame. It can support one 4-port network card. The LF1000 has
Keyboard,
Mouse, and Monitor ports, as well as a 10/100 ethernet network interface
used
for management of the unit.
LF1010 Data Generator
The LF1010 is a 2U (2 Rack Unit) shelf that fits into a standard 19 inch
(wide) frame. It can support up to two 4-port network cards. The LF1010
has
Keyboard, Mouse, and Monitor ports, as well as a 10/100 ethernet network
interface used for management of the unit.

LF1015 Data Generator/Management Machine
The LF1015 is a portable form-factor machine perfect for demo systems and
aesthetic installations. These machines are powerful, and yet run very
quiet
and with their brushed aluminum exterior, they are very presentable. It
can
support up to two 4-port network cards. The LF1015 has Keyboard, Mouse,
and
Monitor ports, as well as a 10/100 ethernet network interface used for
management of the unit.

LF1020 (Ember) Data Generator
The LF1020 (Ember) is a 3x3x3 inch Cube running embedded Linux. It has a
single 10bt ethernet port, a Compact Flash port for a potential wireless
or
wired NIC, and a serial port for the console. It uses very little power
and is
absolutely quiet, as it has no moving parts. You can find more information
about the platform here. The Ember can be used in situations where you
would
like many endpoints spread around your network to test the various
sections or
subnets of your network. For instance, if placed near or in a percentage
of
customer premisis, you could monitor the realtime performance of a VOIP or
other broadband network.

LF1500 Laptop: Data Generator/Controller/GUI
The LF1500 is a Laptop configured to run the Linux operating system. It
can
support two data-generating ports and can run either LANforge-ICE or
LANforge-FIRE. Ideal for a portable network testing and simulation device.
Other portable options may be available: Contact Candela Technologies for
more
information.
LF2000 4-port Network Interface Card (NIC)
The LF2000 is an ethernet card with 4 10/100 auto-sensing ethernet ports.
These are the ports that connect to the system under test.
LF2010 10/100bt Single Port Network Interface Card (NIC)
The LF2010 is a high performance single port Ethernet card. ports. These
are
the ports that connect to the system under test.
LF2020 Gigabit Ethernet Network Interface Card (NIC)
The LF2020 is a Gigabit ethernet card with a fiber interface. These are
the
ports that connect to the system under test.
SW1000 LANforge-FIRE Software Only Port License (100Mbps)
If you wish to provide your own hardware, and load LANforge-FIRE software
on
it, then you can just buy software port licenses. The license cost is
based on
the number of ports, speed of those ports, and the number of machines.
This
can be a very economical way to create a test environment suited to your
particular needs, but it cannot compare with the ease-of-use of
pre-configured
LANforge hardware delivered to your door! This license is for 10/100bt
(100Mbps) and slower interfaces.
SW1001 LANforge-FIRE Software Only Port License (1000Mbps)
If you wish to provide your own hardware, and load LANforge-FIRE software
on
it, then you can just buy software port licenses. The license cost is
based on
the number of ports, speed of those ports, and the number of machines.
This
can be a very economical way to create a test environment suited to your
particular needs, but it cannot compare with the ease-of-use of
pre-configured
LANforge hardware delivered to your door! This license is for
Gigabit-speed
(1000Mbps) network interfaces.
SW1005 LANforge-FIRE: Armageddon Software Only License (100Mbps)
If you wish to utilize the Armageddon accelerated traffic generation
feature,
you must purchase an additional software license for each Armageddon
connection you wish to run simultaneously. This license is for use with
10/100
(100Mbps) or slower speed interfaces.
SW1006 LANforge-FIRE: Armageddon Software Only License (1000Mbps)
If you wish to utilize the Armageddon accelerated traffic generation
feature,
you must purchase an additional software license for each Armageddon
connection you wish to run simultaneously. This license is for use with
Gigabit (1000Mbps) speed interfaces.
SW1010 LANforge-ICE Software Only License
If you wish to provide your own hardware, and load LANforge-ICE software
on
it, then you can just buy software WanLink licenses. The license cost is
based
on the number of Simulated WANs (a pair of two ports). This can be a very
economical way to create a test environment suited to your particular
needs,
but it cannot compare with the ease-of-use of pre-configured LANforge
hardware
delivered to your door!
OS1000 RedHat Linux 7.2 Distribution
The LANforge equipment runs RedHat Linux 7.2. A copy of RedHat Linux can
be
added to any order that also includes any of the LANforge Data Generators
or
Controllers. LANforge comes pre-installed, but the RedHat documentation
should
prove useful for information on how to configure basic things, like the
management IP address, mask, and default gateway information.

Hi,
What is the bandwidth are you having with the satellite link? I don't think this is because of some cable problem. How is your LAN architecture constructed? Are you having a cisco router where the satellite link is terminated? We faced this problem in one of our customer place and we made some configuration to avoid unwanted traffic.
Basically, your satellite link will be of low bandwidth and will be used for low traffic rate application. If there is any broadcast or any ICMP traffic hitting the satellite link, obviously your satellite link will start to flap and you will loose the control.
Better, get a free network management software and poll to the router or any L3 device and find how much you are pumping on to the external interface(satellite link) and finally you will get close to the issue.
Post your finding and some valid output from your findings to further troubleshoot the issue.
PS: Please don't post the entire product manuals or data sheet about your products. If you want to push your product, simply you can paste the link to find it. Everyone who is looking at this forum will have internet connection and can view your products.
Thanks

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